Chuck.



{.COBEY. CHUCK. APPLICATlON FILED JULY 23| 1915. v

Patented June 27, k1916.

THE coLuMBlA PLANouRAPH co.. WASHINGTON. D. C.

Ais

FRANK COBEY, 0F EAST BERLIN, CONNECTICUT.

CHUCK.

Specification of Letters Patent.

Patented Julie 27, 1916.

Original application filed May 14, 1915, Serial No. 28,170. Divided and this application filed July 23, 1915. Serial No. 41,5783.

To all whom it may concern Be it known that I, FRANK CoBEY, a citizen of the UnitedStates, residing at East Berlin, in the county of Hartford and State of Connecticut, have invented certain new and useful Improvements in Chucks, of which the following is a specification.

My invention relates to improvements in chucks, and the object of my improvement is simplicity and economy in construction and convenience and efficiency in use, being divisional of application Serial No. 28,170, filed May i4., i915.

In the accompanying drawing: Figure l is a side elevation of my improvedchuck. Fig. 2 is a front elevation of the same. Fig. 3 is a sectional view on an enlarged s cale on the line of Fig. 2. Fig."4 is a simi- .lar view of thesame with the partsin a different position. Fig. 5 is a sectionalview of the casing, the other partsy being-1n side elevation. Fig. 6 is a side elevation of the backing screw. Fig. 7 is a front elevation of the same.

My improved chuck comprises a spindle member 10, a body 11, a shell 12,' jaws 13, a sleeve nut 14 having an end bearing surface opposed to an end cam sleeve .15 having a coperating end surface that is separated from the sleeve nut 14 by a setv of balls 16, and a backing screw 17. The spindle member 10 has a socket 18 of the usual taper form at the inner vend for receiving a spindle, it being understood that in somecases the saine may be integral with the spindle, and comprises a body 19 at about the middle of the length, having a cylindrical periphery 27, a conical portion 20 extending forwardly from the said cylindrical periphery having a screw thread 21 on the periphery, a reduced cylindrical portion 22 at the inner end, a radial face 23 at the outer end of the tapered or conical screw thread 21 forming an annular shoulder, a short neck 24 extending forwardly from the annular shoulder 23, along the axis, a threaded bore extending through the short neck 24 and inwardly an appreciabledistance,` and preferably as shown, meeting the tapered socket 18, and having the shoulder 26 formed at the junction of the cylindrical portion 27 of the periphery of the body portion 19 with the reduced rear extension 22 in the form of an endV cam, having a serew thread orV helical bearing surface. Theextension 22'has a cirtures: a cylindricalr portion 29 at the rear.

end and middleportions which fits over the cylindrical periphery 27 of the spindle inember 10 and extends an appreciable distance over the extension 22, the extreme inner end of the said cylindricalportion 29l ofthe bore 'being screw threaded, as shown at 30; a

conical portion 31 that fits over the conical portion 21; a'second cylindrical portion 32 vthat' lits over the neck 24; the junction of the portions 31 and 32 constituting a shoulder 33L that abutsagainst the shoulder 23; andV having the bore 32 extend outwardly or forwardly beyond thev neck 24 and the forwardly extending portion beinglprovided with a set off longitudinally extending grooves 34. As shown there are three grooves 34 V-shaped, andspaced angularly at 120 degrees. The body portion 11 is provided with a set of grooves 35, openon the outer side, for the-jaws 13, the same being inclined to correspond to the inclination of the conical surface 21 on the spindle member, andhaving a depth to correspondto the depth of the jaws 13.y

Exteriorly the body portion 11 comprises a conicalperiphery 36 that is flush withthe jaws 13 at the front end portion, an annular, radial shoulder 37 at the inner end, andintermediate the ends an enlarged portion 38 having 'a cylindrical periphery 39 provided with a screw thread adjacent. the conical portion 36, there beingan annular shoulder -at the junction' of thesaid conical portion 36 and they threaded portion 39. Between the `threaded portion`39and the( end shoulder 37 the periphery may be given any finished form' desired.

The sleeve 15 fits between 4the extension 22 and the body portion 11,v has a radial face at the rear end that engages with the balls 16, and on the front. has an end cam surface 45 that is theV counterpart of the end surface 26 on the' body portion 11. The sleeve Vnut has a body portion that is threaded exteriorly to lit the threaded portion 30 kof the bore of the body portion 11 and has a flange y41 at the end that engages with the end shoulder 37, the extreme .front end of the bodyportion of the said nut .14 serving asilo a bearing surface in engagement with the balls 16. The shell member 12 has a bore that comprises a conical portion 42 at the front end that fits over the jaws 13 and the opposed conical portion 36 of the body portion 11 and a threaded portion 43 at the rear end that fits the threaded' portion 39 of the body portion 11, and has a shoulder 44 at the junction of the said portions 43 and 42 that engages with the shoulder 40. The-backing screw 17 has a screw threaded body portion that is a fit for the thread 25 in the neck 24, the said thread 25 being contrary in direction to the thread 43 and in the same direction as the thread 30 and 21. The head 46 of the backing screw 17 is preferably in the form of an equilateral triangle, suitably to provide points at the corners for engaging with the longitudinal grooves 34 in the body portion 11.

The end cam surfaces 26 and 45 as mentioned are helical in form, and comprise one circumferential turn, terminating in each case in a longitudinally directed shoulder 47, the said shoulders coperating by being brought into abutment to limit the relative movement of the sleeve 15 and the spindle member 10 in one direction. The direction of the helical end cam surfaces 26 and 45 is right handed, being contrary to the direction of the screws 30 and 21, so that the shoulders 47 are brought into abutment by a clockwise movement.

The relative movement of the sleeve 15 and the spindle member 10 in the counterclockwise direction is limited by a pin 48 on the spindle member engaging with a shoulder 49 on the sleeve 15. As shown, the said pin 48 extends rearwardly from the face of the end cam surface 26, and the shoulder 49 is formed by cutting a part of the material of the sleeve 15, suitably to form a recess 50 in which the said pin 4S is housed.

The jaws 13 are of appreciable length, fit in the slots 35 in the body portion 11, are formed at the front end suitably to coperate with the matingl jaws to engage a drill or other cylindrical surface, and are provided on the underside with a thread 51 for engaging with the thread 21 on the body portion 11.

The operation is as follows: The body portion 11 and the shell member 12 house the operative mechanism generally, the only other laterally exposed part being the lateral edge portion of the flange 41 on the sleeve nut 14 and the protruding portion of the jaws 13 when in extended position. The spindle member 10 on one side through the medium of the balls 16 and the sleeve 15, and on the other side by the sleeve 12 through the medium of the jaws 13, is free to have a limited longitudinal movement, responsive to the coperation of the end cams 45 and 26 during a rotative movement of the spindle member 10 relatively to the sleeve 15. Such movement operates to effect a quick release of the jaws, and is effected by turning the sleeve 12 relatively to the spindle member 10. A slow movement of the jaws 13 is effected in either direction by turning the sleeve 12, the spindle member 10 being held fixed, by reason of the engagement of the thread 51 on the jaws with the thread 21 on the spindle member 10. On turning the sleeve to close the jaws they are moved relatively to the spindle member as mentioned and they are also carried along outwardly bodily with the spindle member by reason of the cam movement, the shoulders 47 being slightly separated and the jaws and spindle member are locked together. On the reverse movement in effectingl the quick release referred to, because the jaws, shell member, and body member are locked the initial movement results in a coperative member along the cam surfaces, and a bodily separation of the body portion and the shell, thus loosening the hold of the aws, such movement being suflicient to release the hold on a drill or like hard body held by the jaws. The backing screw 17 is carried back and forth with the jaws 13, and the head 46 thereof is in line With the opening for the drill between the jaws, so that the said head will limit the amount a drill can be inserted between the jaws. Because of the to and fro movement of backing screw 17 corresponding to the opening and closing of the jaws the amount the drill can be inserted corresponds to the diameter of the drill.

It is understood that the balls 16 may be omitted and other minor changes made without departing from the spirit of my invention.

It will be noted that the inclined grooves 35 in the body portion-or body member 11, that serve as ways for the aws 13, are positioned angularly mid-way between the longitudinal, parallel V-shaped grooves 34 that. are engaged with the corners of equilateral triangular head 46 of the backing screw or drill thrust member 17. Therefore the middle portions of the sides of the said head 46 are opposed to the said jaws 13. Also lthe said sides of the head 46, as will be noted from Figs. 3, 4, 5 and 6, are tangential to the cylindrical periphery of the body portion of the said backing screw 17 That is to say, the head 16 is flush with the said body portion and is as small as can be made, without cutting below the periphery of the lbody portion of the screw. This permits the jaws 13 to be brought as close as is practicable to the body portion of the backing screw 17 This construction permits the maximum forward thrust of the backing screw 17 with the jaws 13 in the closed position, and at the same time permits of providing an elementary form for the head 46, with straight sides, as shown and described.

I Claim as my invention 1. In a chuck, a head member carrying a threaded portion, a body member rotatively mounted on the said head member, provided with converging longitudinal jaw ways, and having longitudinal grooves, jaws arranged in said ways and having teeth in engagement with the said threaded portion, and

a drill thrust member having the body porv tion threaded into said head member and having a head, the said ]aw-ways,.]aws, and

grooves being each three in number, and

the said head being triangular iny form and having the points engaged with the said grooves. 1

2. In a chuck, a head member carrying a headed portion, a body member rotatively Oopies of this patent may be obtained for mounted on the said head member, provided with converging longitudinal jaw-Ways, and having longitudinal grooves positioned angularly mid-way between the said jaw-ways, jaws arranged in the said Ways and having teeth in engagement With the said threaded portion, a drill thrust member having the body portion threaded into said head meinber and having a head, the said jaw-ways, jaws, and grooves being each three in number, the said headbeing in the form of an equilateral triangle and having the points engaged with the said grooves, and the sides of the said head at their middle portions being flush with the said body portion of the drill-thrust member.

FRANK COBEY.

ve cents each, by addressing the Commissioner of Patents. Washington, D. C. l 

